The NIEHS Training Program in Environmental Health Sciences is in its thirtieth year and has supported 57 current and former pre-doctoral and 26 current and former postdoctoral trainees since 2003. Thirty-seven former pre-doctoral and twenty-one former postdoctoral trainees are in career positions in the private sector/industry, government or academia. There are currently 15 pre-doctoral and 7 postdoctoral trainees. Combined, current and former trainees have published over 280 peer-reviewed papers and book chapters. The need for this Training Program arises directly from the vision statement for the NIEHS that is being refined in the new 2012 Strategic Plan to ... provide global leadership for innovative research that improves public health by preventing disability and disease from our environment. At the core for the implementation of this vision is the need to recruit and train the next generation of environmental health scientists. The Johns Hopkins Training Program is uniquely situated to make important contributions to the national efforts of NIEHS to achieve this vision by being anchored within the large, multidisciplinary Hopkins School of Public Health. In this renewal application, based on the foci of research of the training faculty, the investigators have framed the Training Program into three areas: Molecular Mechanisms of Toxicity; Environmental Epidemiology/Exposure Sciences and Translational Toxicology. Within these three broad areas, the research being conducted by the faculty together with their pre- and postdoctoral trainees addresses one or more of the following topics: a) Mechanisms of disease pathobiology; b) Development and application of biomarkers of the pathobiology (e.g. biomarkers of response, effect, susceptibility); c) Development of prevention intervention and translational strategies; and, d) Environmental disease epidemiology. Within these areas, the research addresses a number of diseases to which environmental exposures contribute including cancer, COPD, asthma, CVD and neurodegenerative diseases. The Program is both interdisciplinary and interdepartmental. Training faculty members involved in the current application are from the Departments of Environmental Health Sciences (EHS), Biochemistry and Molecular Biology, in the School of Public Health and from the School of Medicine's Departments of Oncology and Comparative Medicine. All hold primary or joint appointments in EHS. In this renewal application the investigators are requesting 15 pre-doctoral positions and 4 postdoctoral positions.